Some vehicles are configured to operate in an autonomous mode in which the vehicle navigates through an environment with little or no input from a driver. Such an autonomous vehicle (or AV) typically includes one or more sensors that are configured to sense information about the environment. The autonomous vehicle may use the sensed information to navigate through the environment. For example, if the sensors determine that the autonomous vehicle is approaching an obstacle, the vehicle may be able to navigate around the obstacle. An autonomous vehicle may operate in various weather and lighting conditions, such as, but not limited to, days, nights, good visibility conditions, and/or reduced visibility conditions.